Firstly, a pulverization method, which is a toner production method, is described by way of conventional resin fine particles. The pulverization method is a typical toner production method that has been conventionally employed, and a method in which a toner composition is melt-kneaded by a two-roll or a biaxial extruder, and the melt-kneaded product is cooled, followed by a pulverization treatment of coarse powder, a pulverization treatment of fine powder and a classification treatment, when required, a mixing treatment of external additives such as a fluidizer by a HENSCHEL MIXER, etc. In the pulverization treatment of coarse powder, a ROTOPLEX or pulverizer can be used. In the pulverization treatment of fine powder, a jet mill or turbo mill can be used. In the classification treatment, known production apparatuses such as an ELBOWJET and a variety of air classifiers can be used.
There is a spray method as one of the conventional toner production methods other than the above-mentioned pulverization method. This spray method is a method in which a toner composition is formed into liquid droplets in a vapor phase by using a single-fluid ejection hole (pressurization type ejection hole) sprayer which sprays a liquid from ejection holes by application of pressure, a multiple-fluid spray ejection hole sprayer which sprays a liquid and compressed gases in a mixed form, a rotational disc type sprayer which forms a liquid into liquid droplets by a centrifugal force using a rotating disc, or the like. In the spray method, as a spray-dry system configured to simultaneously perform spraying and drying, a commercially available device can be used, however, when a toner cannot be sufficiently dried, secondary drying such as fluidized bed drying is performed, and when necessary, mixing of external additives such as a fluidizer is performed using a HENSCHEL MIXER etc.
Further, as a conventional toner production method other than the pulverization method, there is a jet granulation method. In the jet granulation method, liquid droplets are ejected from ejection holes each having a diameter as small as the diameter of toner using a vibration generating unit, although a part of forming a liquid into droplets and solidifying the droplets is the same as in the spray method. Conventionally, some jet granulation methods have been proposed. As one of the jet granulation methods, JPO2007-199463 proposed a toner production method, in which the inside of a pressurization chamber is pressurized to generate a liquid column from nozzles, the liquid column is broken into droplets by a weak ultrasonic vibration, and the droplets are dried and solidified to produce a toner, and a toner production apparatus therefor. Such a toner production apparatus generally includes a toner composition liquid-housing container to house a toner composition liquid to be supplied to a pressurization chamber in a liquid droplet jetting unit, and the toner composition liquid-housing container includes a stirring member which stirs the toner composition liquid housed therein to generate a flow. By generating a flow in the toner composition liquid-housing container by the stirring member, respective materials can maintain a uniformly dispersed state in the toner composition liquid, and it is possible to prevent the respective materials from being dispersed with nonuniformity in the toner composition liquid. There is disclosed a toner production apparatus in which a toner composition liquid is pressurized to form a liquid column from through holes, a weak vibration is applied to the liquid column by a vibration generating unit to excite a Rayleigh fission, thereby forming uniform liquid droplets, followed by solidifying the liquid droplets, to thereby produce toner base particles. In the method employing Rayleigh fission, a liquid is pressurized to be ejected, and thus the method has an advantage in that the vibration generating unit is only required to generate a weak vibration, and a toner composition liquid can be formed into droplets with a low voltage.
In a head part disclosed in JP3786034 as a still another example of a toner production method using the jet granulation method, pulse-pressurization is performed to uniformly pressurize the entire system of toner materials stored in a toner material reservoir part for storing the toner materials, and thereby the toner materials are ejected from ejection holes. Hereinbelow, the principles of ejection of liquid droplets disclosed in JP3786034 are outlined with reference to FIGS. 12A to 12E. In FIGS. 12A to 12E, pressure values inside a material reservoir part (a) are described. In the liquid droplet ejecting method disclosed in JP3786034, a toner composition liquid is effected to repeatedly behave three states described below to thereby form liquid droplets intermittently. As a first state, a head part is in a state where no ejection signal is input, that is, as illustrated in FIG. 12A, in a state where no deformation occurs in a piezoelectric body (which may be referred to as piezoelectric element) (b), causing no volume change in a material reservoir part (a), and a material liquid is not ejected from an ejection hole. Next, in a second state, an ejection signal is input, the piezoelectric body (b) undergoes displacement to the inside of the material reservoir part (a), and the material reservoir part (a) decreases as illustrated in FIGS. 12B and 12C. At this time, the pressure inside the material reservoir part (a) is momentarily increased with uniformity, and the material liquid is ejected from the ejection hole. At this time, a flow of the materials is generated from the material reservoir part (a) to the side of a material housing part (not illustrated). Next, as a third state, after completion of the first time ejection of the materials, as illustrated in FIGS. 12D and 32E, application of the voltage is stopped, and the piezoelectric element (b) restores its substantially original shape. At this time, a negative pressure works in the material liquid, and the material liquid in an amount commensurate with an ejection amount is fed from a material housing part called a feeder for housing the material liquid to the material reservoir part (a).
Meanwhile, according to dry process of electric photographic machine, roller and belt and the like for heating is touched dry pattern toner image which is transferred medium like paper medium then toner image on the medium was heated and melted. Then, fixing the toner image onto the medium. Like the above fixing method is well done method because good heat efficiency. According of this fixing method temperature of roller and belt for heating is strong high, so hot offset which is phenomenon for toner is more necessary melted more necessary and fixed to roller and belt is occurred. For prevent to this occurred of hot offset, so far, release type oil as silicone oil coating, roller anb belt for heating for don't occurred to melt and fix.
However the coating method coating release type oil, in this case, the apparatus needs an oil tank and an oil applicator, and therefore the apparatus must be larger and complicated. There is another problem such that the oil applied to the member tends to adhere to copier papers and overhead projection (OHP) films,
Therefore, when water soluble type ink is used to write to copy paper which adhered by oil, there is problem that become bad writable function by cissing water soluble ink, and when projection using OHP, there is the problem that resulting in deterioration of the color tone of the produced images by the adhesive oil to OHP film.
Therefore, as the method which prevent melt and adhered of toner without using oil coating to roller and belt for heat, several methods are proposed that adding release agent to toner itself such as wax.
For example of the above, JPA07-84401 has disclosed toners including a wax having a specific endothermic peak measured by a differential scanning calorimeter (DSC).
JP-A05-341577 has disclosed toners including a release agent such as a candelilla wax, a higher fatty acid wax, a higher alcohol wax, natural plant waxes (a carnauba wax, a rice wax), and a montan ester wax.
However, the toner production method proposed in JPO2007-199463 utilizes Rayleigh fission, and thus when a toner having a small diameter is produced, in order to form liquid droplets having a particle size of about two-times the inner diameter of the ejection hole, the inner diameter of the ejection hole should be made small. Further, this toner production method has a problem that the liquid is pressurized in one direction, and toner components are clogged inside the nozzle depending on the composition of the toner.
In the liquid droplet ejecting method disclosed in JP3786034, a toner composition liquid is effected to repeatedly behave three states described below to thereby form liquid droplets intermittently.
In view of the time spared for the third state and the overall production process time, a time loss occurs, and the liquid ejection method has a problem that the toner production efficiency corresponding to the time loss is reduced.
Further, release agent such as wax of above JPA07-84401, JPA05-341577 are softer than resin and high adhesiveness. Therefore, according to developing process using toner containing a release agent having high adhesiveness, sometimes the added release agent adheres and remains on the organic photoconductor after transfer of the toner image onto the organic photoconductor. Then, there is a filming phenomenon, that adhered release agent contaminates the surface of organic photoconductor.